Abstract

We demonstrate a 120 Gb/s coherent polarization- multiplexed quadrature-phase-shift-keyed transceiver with soft-decision forward-error-correction (SD-FEC) coding based on Turbo Product Code. This industry-first transceiver module utilizes a 40 nm complementary metal-oxide semiconductor (CMOS) application-specific integrated circuit with integrated analog-to-digital conversion, digital signal processing and SD-FEC, and is packaged according to a multi-source agreement from the Optical Internetworking Forum. Through several long-haul and ultra-long-haul system experiments (over 1000 km to 3760 km), we validate the robustness of the transceiver and demonstrate its high tolerance to various system impairments, including fiber nonlinearity, chromatic dispersion up to 60,000 ps/nm, polarization mode dispersion, polarization-dependent loss, polarization transients and multiple-path interference.

(Color online) Measured additional OSNR penalty (defined in the text) versus PDL for the 10 × 100 km systems with PMD and PDL elements (red squares) and with PMD elements only (green diamonds). The black curve shows a separate measurement with first-order PDL only, where the OSNR penalty is the difference in required OSNR to have no uncorrectable FEC blocks with and without PDL.

(Color online) Measured pre-FEC BER versus OSNR, with and without polarization launch scrambling or switching, after transmission over 10 × 100 km without (first set of four curves with markers) and with the inter-stage PMD and PDL elements (second set of four curves with markers).

(Color online) Measured line-side pre-FEC BER after 47 × 80 km transmission without (red curve) and with additional noise loading at the receiver (green curve). Zero errors were recorded on the 100G client-side test set during the soak tests.